Vat dyestuff.



tlTiNl'lED TATE PALEET I WILHELM BAUER, OF VOHWINKEL, AND ALFRED HERRE, OF ELBERFELD, GERMANY, .ASSIGNORS T0 FARBENFABRIKEN VOR-M. FRIEDR. BAYER & (10., OF ELBERFELD, GERMANY, A CORPORATION OF GERMANY. v

VAT DYESTUFF.

No Drawing.

To all whom "it may concern:

Be it known that we, VILHELM BAUER and ALFRED HERRE, doctors of philosophy, chemist-s, citizens of the German Empire, residing at, respectively, Vohwinkel and Elberfeld, Germany, have invented new and use ful Improvements in v at Dyestuffs, of which the following is a specification.

Our invention relates to the manufacture and production of new and valuable vat dyestutls. They are obtained by condensing halogen substituted isatin derivatives containing the halogen in the benzene nucleus in which the oxygen of the alpha-keto group is replaced by easily movable or replaceable substituents, e. f]. halogen, sulfur, the amino group, the allroxy group, with l-naphthol compounds, especially l-naphthol and its substituted derivatives having a free ortho position to the hydroxy group.

The new dyes are in a dry state dark blue crystalline powders with a metallic luster which are soluble in hot nitrobenzene generally with a blue coloration, and which yield with hydrosulfite and caustie'soda lye vats dyeing cotton after exposure to air blue shades remarkable for their fastness to chlorin.

In order to illustrate the new process more fully we can proceed as follows, the parts being by weight c-l00 parts of dibromoisatin are converted in a dry benzene suspension into dibromoisatiuchlorid by heating it with 72 parts PCl The mixture thus obtained is then poured into a solution which is well stirred. of parts of l-uaphthol in dry benzene. 'lhe stirring is continued for a short time and the dye which separates on cooling is filtered oil and washed. It is a dark blue crystalline powder with a copper luster scarcely soluble in hot benzene with a pure blue, and in concentrated sulfuric acid with a greenish-blue coloration. It yields with hydrosullite and NaOH a yellow vatfrom which cotton is dyed yellow changing on exposure to air into a tast deep reddishblue fast'to chlorin.

Specification of Letters Patent.

Application filed September 8, 1909.

Patented June it, into.

Serial No. 516,685.

Other naphthol compounds may be used,

e. 9., 4-ethoxy-1-naphthol; and instead of the above isatin derivatives others may be used, c. g., chloro-, bromo-, chlorobromoor dichloroisatin chlorid, ortho-bromo-paramethylisatin chlorid, tri-bromo-isatin chlorid, para-bromo-ortho-methylisatin chlorid, etc., etc.

We claim 1. The herein-described new dyestufis obtainable from a halogen substituted isatin derivative containing the halogen in the benzene nucleus in which the oxygen of the alpha-keto group is replaced by easily movable or replaceable substituents and a hereinbefore defined 1-naphthol compound, which dyestuffs are in adry state dark blue crystalline powders with a metallic luster which are soluble in hot nitrobenzene generally with a blue coloration, and which yield with hydrosulfite and caustic soda lye vats dyeing cot-ton after exposure to air blue shades remarkable for their fastness to chlorin, substantially as described.

2. The herein-described new dyestutl' obtainable from dibromoisatinalpha-chlorid and l-naphthol, which dyestufi is in a dry state a dark blue crystalline powder with a copper luster, scarcely soluble in hot benzene with a pure blue and in concentrated sulfuric acid with a greenish-blue coloration, and whit yields with hydrosulti'te and canstic soda lye a yellow vat from which cotton dyed yellow changing on exposure to air into a deep rcddislnblue ren'iarlrable for its fastncss to chloriu, substantially as described.

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses.

WILHELM BAUER. (n. 5.} i LFRED HERRE.

Witnesses 2 )r'ro home, WILLY KLEIN. 

